Dandy roll construction



- May 2, 1933.

J. A. SPENCER DANDY ROLL CONSTRUCTION Filed June 27, 1932 2 Sheets-Sheet 1 ATHT 4) M !\\/l\\ M U U)UU UUUUJI HFU INVENTOR Jomv 14.5PENCER AITORNEYS may 2, 1933.

J. A. SPENGEFN DANDY ROLL CONSTRUCTION Fi led June 27, 1952 2 Sheets-Sheet 2 INVENTOR JoHNA.5P/vcR BY a 40M ATTORNEYS Patented May 2, 1933 UNITED STATES .J'QHN A. f5]?ENCER, OF SOUTH HADLEY FALLS, MASSACHUSETTS DANDY ROLL- CONSTRUGTION iv Application filed June 27,

Thisinvention relates to improvements in watermarking devices or dandy roll design marking used in the paper making art. It is now common inthe artto use what is called a dandy roll. This, is a cylindrical frame covered with a wire screen, and the screen is either plain or on the screen is the design for the watermark. .The operation of such a device is well known to those skilled in the art, as it is the most common of watermarking structures in present day use. The plan of invention is to improve the dandy roll construction.

The features of invention can be best understood from a description of the accompanying drawings.

Fig. 1 shows my dandy roll frame but without any winding wire such as is commonly provided to cover the frame and properly support the dandy roll screen;

Fig. 2 shows my winding wire for supporting the dandy roll screen;

Fig. 3 shows my dandy roll screen; Fig. l shows a modified form of winding wire;

Fig. 5 is a detail view; and

Fig. '6 is a detail.

It has been a common practice to notch the rods 1 of the dandy roll frame and wind :1 wire tightly around'the frame in spiral form with turns spaced as in Fig. 2. Then a screen such as in Fig. 3 has been attached to the winding wire for support and the frame with these parts have mounted to rotate on the continuously moving sheet of paper being made. The rotation of the roll is caused by resting it on the paper stock at the place where the watermark is to be applied to the moving sheet. As the paper stock reaches this place in a paper making machine, the sheet is carrying a. lot of water, which is leaving the stock rapidly so as to mat the fibers at the dandy roll location.

I have found that the rods such as 1 of the frame act as paddle wheels and churn up the water where the watermark is applied. This interferes with thebest application of the watermark, and also the best formation of the sheet in which the dandy screen has a part. 5 instead of having my Winding wire 1932. Serial No. 619,374.

mounted in notches of rod 1, I llELVG't'hB winding wire ride above rods 1. Then'the screen on the outside of thewinding wire holds rods 1 further away from the water on the paper making or Fourdrinier wire.

To hold the winding wire 2 in its coiled cylindrical form I provide wires 3 (smaller than-rods 1) soldered to the coils and spaced farther apart than rods 1. There are four wires 3 where there are eight rods 1. This arrangement avoids the objectionable feature of churning the water on the paper where the watermark is applied. It is an arrangement I prefer to use in connection with the other forms of winding wire construction that will be described later. I

\Vith the parts made as in Figs. 1,2, and 3., I assemble them by telescoping the cylindrical screen 4 on the cylindrical winding wireQ. The latter holds the screen in true cylindrical form and supports it firmly enough to maintain such form in use which the frame 1 alone would not do. The assembly thus made telescoped onto the frame with wires 3 offset from rods 1; A relative. turning of the "frame will bring a wire 3 into driving position against a rod 1 so the frame-and wi're will rotate together as the dandy roll moves with the paper sheet in the machine. There is sufficient frictional engagement between the screen and winding wire 2-to drive the roll'upon rotation of the screen part. And there is also a riding up of wire 3 on rod 1 as by a cam action due to the rounded wire and rod ofxdilferent sizes. I have found it of considerable advantage to mount the screen on the frame in a loose enough manner to permit a slight axial movement relatively to the roll frame. The winding wire and screen are together of much less weight than the other parts of the .dandy roll. A paper making machine undergoes a lot of shaking in its operations as it is making the sheet. To make a watermark or to help form the web, a dandy roll screen should merely'roll on the paper stock. But due to the shaking and the weight of the dandy roll there isatendency for a movement that mars the impression of the water= mark or changes the pressure of the screen .09

on the forming web. To minimize this tendency I have provided for a slight axial play between the dandy roll screen and its frame. I do this by having a flange 5 on the frame against which one end of the winding wire and its screen can abut. The frame is a little longer than the winding wire and screen. At the end opposite to flange 5 I provide a flattened screw head 6 mounted in frame as in Fig. 4. I can turn the head 6 up to serve as a fingerto retain the winding wire and screen on the frame. But since the frame is somewhat longer than the screen, the latter is permitted a little play before it is stopped by the flange 5 at one end and the head or finger 6 at the other. The screen is What carries the watermark design. So if the shaking of the machine starts to move the dandy roll relatively to the paper the screen (within its permittedplay) can stay on the paper without axial movement relative to the paper it is marking. The idea is that the screen can find and follow its position on the paper easier if it is not required to move with the. dandy roll frame in every instance. There is a flexibility in the mounting of the dandy roll screen on its frame that gives a more certain watermark. It is a spring floating action with the floating parts (cage and screen) of light weight as compared to the weight of the rotating dandy roll as a whole.

In the use of dandy rolls, it is frequently desired to changewatermarks. This needs to be done with convenience and economy in dandy roll equipment. By my construction I can turn screw 6 so that my dandy roll screen and winding wire can be slipped off the frame. Then another can be slipped on bearing the new watermark and the screw 6 turned up as a finger to hold it on.

In a wide paper making machine it is customary to have the same dandy roll provided with dififerent watermarks for spaced bands of thepaper that are cut apart after leaving the machine. Instead of having a single cylinder made up of one winding wire and one screen I can provide a plurality of shorter ones totaling the same length. These can be taken off and put on the roll frame in exactly the same way as the single screen and the same flange 5 and finger 6 will hold them in place.

By the arrangement I have described, the paper making machine can be supplied with a single dandy roll. The mark to be applied can be carried by the dandy roll wire. The number of cylindrical wires can be multiplied according to the number of marks. All that is necessary in changing marks is to supply a new wire with the new mark on it. The dandy roll itself is made in extremely simple and inexpensive form according to my invention. And yet it will ser e to t ke a ew sci-sen q k y and COD:

veniently when a new or different mark is desired. I am aware that I am not the first to make a dandy roll with interchangeable wires for changing watermarks. My invention in this respect rests in the means found in the improved way of doing this. It is inexpensive, requires no particular precision of parts (except a substantially cylindrical form), and is extremely simple to make and manipulate. My invention in respect to separating the lighter screen cylinder from the more rigid dandy roll frame so as to allow play enough to let the watermark design ride better in rotating over the moving paper I believe to be basically new.

The preferred form of my invention is indicated in Fig. 5. It has an additional feature which I will now describe. This is a provision for automatically tightening the dandy roll wire and maintaining it tight whenever the dandy roll is operated. In my view this feature is the most important of my present invention. In a sense it is independent of the other features although my par.- ticular means for practicing it is by a small variation in the arrangement of the winding wire I have already described.

As shown in Fig. 5, the winding wire is made up as before except that the cylindrical cage is split at 10. The ends of the cut coils on one side of the slit are soldered to a wire 3 and the ends on the other side to another wire 3. The split wire frame is preferably teleseoped with a cylindrical wire screen bearing the watermark design, put on the frame and held on, all as described in connection with Figs. 1 to 3.

The new dandy roll combination is driven by contact between the screen and paper. As the screen rotates it moves the cage wires 3 toward wires 1 of the frame and wire 3 will try to ride up on wire 1 due to their opposed rounded sides which serve as cam surfaces. This action will spread the split cage and tighten the cage on the wire. Spreading the split cage tightens the wire and the constant action of the rotating screen holds it tight.

While the cam action between wires 1 and 3 will function, I prefer a different way to secure this spreading action on the cage. The different Way is to make an inward bend in a few of the curved wire turns midway between each pair of the wires 3 in the cage. This is indicated in Figs. 4 and 6. Such bends will provide on the cage a series of in wardly directed spring cams. It is preferable not to bend all the wires for this purpose but only enough of them to give a longitudinal series and an equally spaced circumferential series. Then when the cage is telescoped on the dandy frame and starts to rotate, the followingaction takes place. The spring cams of the cage meet and contact with one or moreod 1 of t fr me The t rm ing action cams the split cage apart with a spreading action. This tightens the cage against the cylindrical screen, tightens the screen, and continues a tendency to tighten the screen all the time the dandy roll is r0- tating. This is just what is wanted. It prolongs the life of dandy roll screens.- And itavoids a lot of repair and replacement work. Furthermore, it insures the design tightness whenever the dandy roll screen is applying its watermark.

The economy of use is shown by the fact that a screen unit can be replaced on my dandy roll whenever a new mark is desired. It is not necessary to change any other parts of the dandy roll. The split sleeve makes this change easy and rapid to make. The same interchange of parts can be accomplished with the unsplit sleeve of Fig. 2, but not so conveniently as with the split sleeve of Fig. 5. In the unsplit sleeve it is desirable to have the cylindrical form very slightly tapered from one end to the other so that the screen will go on and come off more easily in the changing of watermarks. Furthermore, I can adapt my invention to many forms of standard dandy roll constructions. The latter can be stripped of their screen and winding wire. Then I can supply one of my winding wire cage units, slightly larger than the old dandy roll frame. The driving connection between the frame and cage is preferably secured by making enough inward cam-like bends (see Fig. 6) so as to yieldingly engage any longitudinal rod of the old frame. A separable dandy screen unit can be put over the winding cage unit and the new parts removably held in position as indicated in Fig. 4:. Thus, the invention has the advantage that it can be put to use without scrapping the dandy roll con structions already in wide use. Except for a replacement of parts forming a small part of the total value in the old equipment that is made to operate with convenience and economy of the new equipment.

There are some refinements in my new construction which I will now disclose to enable the best use of the invention as I have discovered by experiment and test. It is known that the dandy roll operation is important in paper making apart from the application of watermarks. The roll ordinarily rests on the stock above the Fourdr-inier wire at the place where the sheet is first matted together, that is at the initial formation of the wet web of paper. Before reaching. the roll the fibers are for the most part floating in the water. Upon reaching the roll the water is leaving the paper so rapidly that the fibers are matting together under the roll. The latter is usually located in front of and very close to that one of the suction boxes where it is. desirable to change the state of the fibers from their floating to their matted condition in the paper formation. The Fourdrinier wire gives the desired surface to the paper web at the bottom andthe dandy roll screen ordimind, I have devised means to hold the dandy roll screen with these features, which willbe apparent in part from the construction I have already described, and in part from the refinements I will emphasize. The .Winding wire cage that holds the screen is yieldingly mounted on the frame. The driving connection between the two is formed by the contact of a frame rod with the cam spring portions of the cage. larger than the frame) tends to ride the frame upon a single line of contact with one of the rods. This line contact is a yielding one. The winding cage as a whole is flexible and yielding. I make it with the wires connecting the coils small enough so that the cage is quite springy. For example, if supported at one end alone the other end will by gravity be a few inches below the supported end somewhat like a rubber hose of the same size. lVith this flexibility in the cage and the spring support between the cage and the stiff cylindrical dandy frame, the flexible dandy screen is applied to the upper surface of the forming paper Web by a pressure line contact with a readily yielding characteristic. The yielding function is of sufficient degree to permit the line of screen contact to finda better pressure contact with the forming web of paper. one that will be more uniformly applied to the paper and give the latter a better surfacethan the old dandy roll constructions. The new dandy roll will have much lesstendency than the old to bound in operation. It will absorb the shocks due to operation of the paper making machine and keep its screen pressureon the web. When the-screen bears watermark designs the pressure of these on the web is intermittent. The yielding nature of my screen mounting will accommodate itself to this intermittent pressure bet ter than the old dandy rolls and avoid jumping.

The longitudinal wires holding the cage coils in position are small enough to be flexible and a lot smaller than the longitudinal stiff rods of the frame. They are each round and the small wires for this reason will have a greater cam riding action when they are used for the driving connection between the two. I prefer, however, to use the cam bends in the winding wire, indicated in Fig. 6, as the driving connection. These can be readily formed in the slit cage of Fig. 5 or in the unsplit cage of Fig. 2. In the former they have The latter (being slightly the function of expanding the winding wire cylinder'to tension the screen in addition to driving the frame by Contact with the frame rods. By using the coils of the winding screen for making my spring'cam parts I am enabled to adapt a dandy roll to its particular use as the cams can be bent in at any time to adjust the spring cam action to what is wanted. The cams are adjustable in the sense tl'iatthey are so easy to form that they canbe changed in shape by pliers after the dandy roll goes into use and by the Workman at the Fourdrinier machine.

Having fully disclosed and described my .invention, I claim:

1. A dandy roll comprising a skeleton cylindrical frame, a removable coiled wire cage for telescopic mounting on the frame, a removable design carrying screen for telescopic mounting on the wire cage, said frame,

cage, and screen, being all individually made as separate unitary parts for quick telescopic assembly and separation of all such parts.

2. A dandy roll comprising a skeleton cylindrical frame, a removable coiled wire cage'fo'r telescopic mounting on the frame, a design carrying screen for telescopic mounting on the wire frame, said cage and screen being slightly shorter than the frame and mounted on the latter for a limited axial play with respect to the frame during rotatable operation of the parts.

3. A dandy roll comprising a skeleton cylindrical frame having a series of wires on the outside surface parallel to the axis, a removable coiled wire cage of cylindrical form for telescopic mounting on the frame, said cage having a series of wires fastened on the inside of its coils parallel to their axis, a design carrying screen carried on the outside of said coils, the cage and frame being fitted together when their respective series of axially parallel wires are all circumferentially ofiset and in their fitted condition having said series of wires overlapping in a direction radial to the cylinder. 4. A dandy roll comprising a cage for supporting the cylindrical design screen, said cage made up of a series of closely spaced helical turns of a wire held in position by a few straight wires attached in spaced relation and parallel to the cage axis on the inside surface of said coils, a rotatable dandy frame arranged for telescopic assembly and removal of said cage, means to hold the parts in operative position, said cage and frame in such position being free for limited relative movements in both axial and circumferential directions, and a design carrying screen for mounting on said cage.

5. A dandy roll construction comprising a cylindrical supporting frame with axle portions at the ends, a wound wire cage adapted for telescopic unit assembly and removal with the frame, cooperating means on the frame and cage for the rotation of one to cause the rotation of the other, said means permitting a limited relative rotation of the frame and cage and a dandy roll screen for covering the cage.

6. A dandy roll construction comprising a cylindrical supporting frame with axle portions at the ends, a woundwire cage adapted for telescopic unit assembly and removal with the frame, cooperating means on the frameand cage for the rotationof one to causethe rotation of the other, said means permitting a limited relative rotation of the frame and cage and a dandy roll screen for covering the cage, and means to hold the frame and cage together for operation and release the parts for unit separation.

7-.- A dandy roll construction comprising a cylindrical supporting frame with axle portions at the ends, a wound wire cage adapted for telescopic'unit assembly and removal with the frame, cooperating meanson the frame and cage for the rotation of one to cause the rotation of the other, said means permitting a limited relative rotation of the frame and cage and a dandy roll screen for covering the cage, and means to hold the frame and cage toge her for operation and release the parts for unit separation. said means being arranged to permit a relative axial displacement of the units during the period oftheir rotation together.

8. A dandy roll construction comprising a cylindrical frame and a cylindrical design carrying screen to cover the frame, means between the frame and screen operable upon rotation ofthe parts to tighten the screen.

9. A dandy roll construction comprising a cylindrical frame and a cylindrical design carrying screen to cover the frame, means between the frame and screen operable upon rotation of the parts to tighten the screen, said means being operable upon stopping the dandy roll to release the tightening strain on the screen.

10. A dandy roll construction comprising a cylindrical design bearing screen, a split sleeve to support and carry the screen, said sleeve being made of a series of closely spaced helical coils of spring wire with the coils cut on a line topermit cylindrical expansion and contraction and means to' hold said coils together for such action.

11. A screen support for assembly in a dandy roll, said support comprising a series of closely spaced spring rings and means to hold them in spacedfposition to form a cylindrical' skeleton'support, said rings being split and mounted on said holding means so as to permit spring contraction and expan-v sion for tightening and loosening a screen mounted on the support.

12. A screen support for assembly in a dandy roll, said support comprising as'eries of closely spaced ring-s formingacylindrical skeleton for carrying the dandy roll screen, said rings being split to permit circumferential expansion and contraction, in combination with a dandy roll frame and means cooperating between the frame and rings tending to expand the rings as the screen and frame rotate together.

13. A screen support for assembly in a dandy roll comprising a cylindrical skeleton frame made up of turns of spring wire, said turns being split to permit the frame to expand and contract its cylindrical form, some of said turns having small cam-like bends extending inwardly from its cylindrical surface whereby said bends can be operated upon to expand the frame when the latter is used to support a paper marking screen.

14. A dandy roll comprising in combination two circular head members having axles for rotatably mounting the roll, parallel spaced rods attached at opposite ends to the circumferences of said members to form a dandy frame, a removable screen carrying frame made up of a series of closely spaced helically coiled turns of spring wire having longitudinal wires attached on the inside of the turns to hold them in position, said turns being cut transversely with each opposed series of free ends attached to a separate one of the longitudinal wires whereby the coiled frame is capable of cylindrical expansion and contraction, said frame telescopically fitting the dandy frame, some of said spring wire turns provided with inwardly bent small cam portions adapted to ride up on said spaced rods and expand the screen carrying frame with a spring action when the dandy roll is in operation, a design carrying screen telescopically fitting the expansible frame, said screen being mounted to be tight ened up and held tight by the action of its expansible frame during dandy roll operations.

15. A dandy roll comprising in combination two circular head members having axles for rotatably mounting the roll, parallel spaced rods attached at opposite ends to the circumferences of said members to form a dandy frame, a removable screen carrying frame made up of a series of closely spaced helically coiled turns of spring wire having longitudinal wires attached on the inside of the turns to hold them in position, said turns being cut transversely with each opposed series of free ends attached to a separate one of the longitudinal wires whereby the coiled frame is capable of cylindrical expansion and contraction, said frame telescopically fitting the dandy frame, some of said spring wire turns provided with inwardly bent small cam portions adapted to ride up on said space-d rods and expand the screen carrying frame with a spring action when the dandy roll is in operation, a design carrying screen telescopically fitting the expansible frame, said screen being mounted to be tightened up and held tight by theaction of its expansible frame during dandy roll operations, said cam portions being designed to relieve the screen from its maximum tension when the parts stop rotation.

16. A dandy roll comprising a skeleton cylindrical frame, a removable coiled Wire cage for telescopic mounting on the frame, a design carrying screen for telescopic mounting on the wire frame, said cage and screen having spring mounting driving connection with said frame.

17. A dandy roll comprising a skeleton cylindrical frame, a removable coiled wire cage for telescopic mounting on the frame,

a design carrying screen for telescopic mounting on the wire frame, said cage being loose on said frame and having spring cam portions serving as a flexible driving connection between the two. i

18. A dandy roll comprising a skeleton cylindrical frame, a longitudinally flexible spring wire cage of cylindrical form larger than the frame and mounted thereon so as to permit such flexibility, spring driving parts between the frame and cage tending to hold the cage and frame in parallel cylindrical form but permitting variations therefrom in operation whereby the cage can apply a dandy screen to a paper forming web with a yielding action beyond what the screen alone will give.

In testimony whereof I have affixed my signature.

JOHN A. SPENCER, 

